[RFC PATCH 2/4] powerpc: kprobe: add arch specific blacklist

[Michael Ellerman]

"Naveen N. Rao" <naveen.n.rao at linux.vnet.ibm.com> writes:

> Add symbol to mark end of entry_*.S and use the same to blacklist all
> addresses from kernel start (_stext) to entry code from kprobes. Much of
> this code is early exception handling where we can't really take a trap.

I'm not sure about this. entry_*.S is actually a bit of jumble,
especially the 64bit version. I've been wanting to split it up for a
long time.

It doesn't actually contain any early exception handling. It does
contain the common syscall handler, and the exception return paths, some
of which should be black listed. And lots of other junk.

Also I'm not sure if it's guaranteed that there won't be other code
between _stext and the end of entry, it's not handled explicitly in the
linker script, it just tends to get linked early because it's in head-y.

So I think it would be better if we had a clearer picture of exactly
what in this file we want to blacklist.

cheers